Rock drill



Nov. 13, 1928. 1,691,406

c. F. OSGOOD ROCK DRILL Filed June 2, 1927 Invmz2ar: dimrlasl? 05900617;

hatented Nov. 18,

UNITED STATES PATENT OFFICE.

CHAR-LES F. OSGOOD, OF CLAREMON'I NEW HAMPSHIRE, ASSIGNOR TO SULLIVAN MACHINERY COMPANY, A CORPORATION OF IYIIASSACI-JIU'SETTS.

nocx DRILL.

Application filed June 2,

This invention pertains to rock drills and more particularly to a hole blowing device for a fluid actuated rock drill of the hammer device including means whereby the resisting throwing pressure at one end of the fluid distribution valve is vented to atmosphere, thereby permitting the valve to be manually shifted and held immovable with facility. These and other objects and advantages of this invent-ion will, however, more fully appear.

In the accomp anying drawing I have shown for purposes of illustration one form which the invention may assume in practice.

In this drawing,-

Fig; 1 is a central, longitudinally extending'. vertical sectional view taken through a rock drill embodying the improved hole blowing device, the parts being shown in position to effect a hole blowing operation.

Fig. 2 is a fragmentary sectional view similar to that shown in Fig. 1 with the parts shown in a different position.

In this illustrative construction there is shown a rock drill of the fluid actuated hammer type comprising a cylinder 1 having a bore 2 in which is reciprocably mounted a hammer piston 3. The piston 3 is provided with a forwardlv projecting striking bar 4:

extending through a bore 5 formed within a usual front cylinder head 6. The striking bar 1- is adapted to impart a series of blows to the shank of a hollow drill steel '2' I herein of hexagonal cross section. The drill steel 7 is loosely mounted in a usual manner within a hexagonal opening formed in a chuck bush: ing 8 secured to a chuck sleeve 9 rotatably mounted within a usual chuck housing 10. As illustrated, the rear end of the cylinder bore 2 is closed by a washer 11 while interposed between this washer and a rear head member 12 is a usual ratchet ring 13 to be later referred to. The chuck housing 10,, the front cylinder head 6. cylinder 1, rear washer. 11, rear head 12, and the ratchet ring 13 are 1927. S erial No.196,110.

held in assembled relation in any suitable ard convenient manner, for instance by usual side rods or bolts (not shown). I

v The cylinder 1 has preferably formed integral therewith a valve chest 14 having a bore 15 herein arranged parallel with the cylinder bore. Disposed withinthe bore 15 are oppositely positioned sleeves 16 and 17 each having an enlarged central bore 18 and a reduced outer bore 19. As shown in Fig. 1 the sleeve 16 has suitably secured thereto a valve buffer plu 20 while secured to the sleeve 17 is a buffer plug 21 held in position by a suitable nut member 22. Reciprocably mounted within the bores 18 and 19 formed in the sleeves 16 and 17 is an automatic fluid distribution valve 23 herein of the well known three spool differential type having reduced end spools 24 and an enlarged central spool 25, the central spool being mounted in, the bores 18 while the end spools are mounted in the bores 19. vReciprocable movement of the valve 23 in opposite directions is limited by the buffer plugs 20 and 21. The central spool 25 of the Valve shown controls a central inlet port 26 while the end spools 24 re spectively control usual exhaust ports 27 and 28 formed at the opposite sides of the inlet port 26 and leading directly to atmosphere;

Motive fluid for actuating the piston 3'is supplied and exhausted from the rear and front ends of the cylinder bore 2 through combined supply and exhaust passages 29 and 30 respectively communicating with the valve, chamber on opposite sides of the central inlet 26. The action of the distribution valve 23 is controlled by usual crossed throwing passages 31 and 32, the former connecting thefront end of the cylinder bore with the bore at the rear end of the valve, while the throwing passage 32 connects the rear end of the cylinder bore with a bore at the front end of the valve. These throwing passages are controlled by the piston 3 and are employed for alternatively admitting pressure fluid from the cylinder bore to. the opposite ends of the distribution valve to effect reciprocation thereof, the pressure fluid admitted to the passage 31 throwing the distribution valve forwardly while the pressure fluid admitted to the passage 32 throws thev valve rearwardly all in'a well known manner.

The hollow drill steel 7 is adapted to be intermittently rotated during reciprocation of the hammer piston and this is accomplished by a usual ratchet and pawl mechanism including a rotatable pawl carrier 33 carrying projecting forwardly t irough the washer 11 ".Tfltl within the rear end of the cylinder here is a rifle bar 35 having spiral grooves 36 on its periphery. The spiral grooves 36 cooperate with spiral keys 37 carried by a rifle nut hreadedly connected within the rear end of "h hammer piston 3. As shown, the strik ng bar l of the piston has formed on its periphery straight longitudinally extending grooves 39 which cooperate with straight keys lO carried by a chuck nut ll threadedly connected to the chuck sleeve 9. During forard movement of the hammer piston3 the pawls of the pawl carrier slip over the teeth on the ratchet ring 13 andconsequently the hammer piston delivers an unimpeded blow to the shank of the drill steel 7. Upon the return stroke of the hammer piston the pawls engage the ratchet teeth 34 thereby positively prevent ng rotation of the rifle bar and consequently during this return stroke of the piston the latter is slightly rotated. Rotation of the piston is transmitted through the straight grooves 39 on the strikingbar, stra ght keys 40 on the chuck nut, the sleeve 9 and the chuclr'bushing 8 and consequently the drill steel is rotated. The construction described above is usual in rock drills of the type d sclosed and further description of the 1 same is herein considered unnecessary.

The improved hole blowing device comprises a reciprocable plunger valve 42 arranged coaxially with the distribution valve portion of the valve 12 extending through the bore 1-3 in the distribution valve and the bore a l in the buffer plug 20 is reduced, thereby leaving a shoulder or abutment 46 adapted to engage the forward end surface of the distribution valve as hereinafter described. The plunger-valve 4:2 is externally grooved at 47 at itsreaiwvard end and is provided at its forward end with a conveniently located push button 4h As shown, the buffer plug 20 has formed therein radial ports 49 connecting the bore 4- 1 with the bore 19 at the rear end of the distribution valve 23, while also formed in this buffer plug and the valve sleeve 16 are radial ports 50 which connect the bore 44 with the atmosphere. In this instance, the plunger valve, 412 is held in its released or inoperative position as shown in Fig. 2 by means of a coiled spring 51 seated within a bore 52 formed in the buffer plug 21 and engaging a transverse pin carried by the valv 42 The plunger valve 4 2 has formed centrally therein restricted vent passages 5 1 surface of the central spool 25 of the dis-- tribution valve 23 and through the passage 29 to the rear end oi? the cylinder bore 2 where it acts on the rear surface of the piston 3 and moves the latter forwardly to strike a blow on the dri 1 steel .7, The exhaust from the front end of the cylimler bore 2 flows out through the passage 3) past the rear surface oil the forward spool 2a and 'hrough the exhaust pas age 23 to atmosphere. The distribution valve 23 is held in its forward position against the front butler plug 21 by reason of the larger effective area of the central spool 25.

- hen the piston 3 uncovers the throwing passage 32 pressure fluid is admitted from the cylinder bore to the forward end of the distribution valve 23 and consequently the latter is thrown rearwardly against .the rear buffer plug 20 as shown in F 1. Pressure fluid now enters the forward end of the cylinder bore through inlet passage 26 past the forward surface of tie central spool on the distribution valve and through passage 30 and consequently the hammer piston is moved rearwardly. Tl e exhaust now takes place through passage 29 past the forward surface of the rear spool 24 and through the exhaust passage 27 to atmosphere. The plunger valve 1-2 is in its released or inoperative position at this time as shown in Fig. 2 and the restricted vent ports 54, 55 therein prevent any back pressure from building up in the bores at the ends of the valve and as a result the'valve action is materially quickened. As soon as the piston 3 has uncovered the throwing passage 31 the distribution valve 23 is again shifted to its forward position and this cycle continues tl'iroughout the normal operation of the drill.

lVhen it is desired to effect a hole cleansing operation, the operator presses against the push button 48 and moves the plunger valve 1-2 rearwardly trom the position shown in Fig. 2 until the groove l-T connects the ports 49 and 50 and consequently the pressure fluid in the bore at the rear end of the distribution valve 23 tending to throw the latter forwardly is vented to atmosphere. Upon further rearward movementof the plunger valve the shoulder 4-6 directly engages the forward end surface of the distribution valve, the "eby permitting the latter to be manually shiftec with facility against the relatively small op posing pressure acting on the central spool 25. hen the distribution valve v23 is-held in its retracted position as shown in Fig. 1, sure fluid flows from the inlet 26 past the forpresward surface of the central spool 25 of the distribution valve and through the passage 80 to the forward end of the cylinder bore. The continuous pressure flowing to this end of the cylinder bore forces the hammer piston 8 rearwardly againstthe rear cylinder washer ll and consequently pressure fluid then flows from the cylinder bore through the flutes 39 on the striking bar 4e, through the chuck nut all, and thence through the bore in the drill steel '7 to the bottom of the drill hole. As soon the m anual pressure on the push button :38 is released, the plunger valve 42 is automatically returned to its inoperative position by the spring 51 and the distribution valve 23 then resumes its normal operation and the drill will again function in a normal manner.

As a result of this invention it will be noted that an improved hole blowing device is pro vided whereby the distribution valve can be actuated and held without material resistance and without the necessity of manually shift ing the valve against the relatively great resisting throwing pressure. It will further be noted that by venting the space at the rear end of the valve to atmosphere it is possible to manually shift the distribution valve rearwardly with facility, it being only necessary to move the valve against tl e relatively small opposing pressure acting on the central spool or the valve. These and other advantages or this invention will be clearly apparent to those skilled in this art.

While l have in this application specifically described one form which my invention may assume in practice, it will be unuerstood that this form has been shown for purposes of il lustration and that the invention may be modilieu and embodied in various other forms ithout departing from its spirit or the scope he appended claims.

vi hat 1 claim as new and desire to secure by Letters Patent is: l

1. In a fluid actuated rock drill of the hammer type, the combination of a cylinder and a piston reciprocable therein, a valve chest and a fluid distributing valve therein controlling both the supply and exhaust of pressure fluid for said cylinder, valve throwing passages between opposed spaces in the valve chest and the cylinder bore for supplying pressure fluid for actuating said valve, and a hole blowing device including means for venting the space at one end of the valve to atn'iosphere during a hole blowing operation and for directly engaging said valve to shift it toward said end and hold the same immovable.

2. In a fluid actuated rock drill of the hammer type, the combination of a cylinder and a piston reciprocable therein, a valve chest and a fluid distributing valve therein controlling both the supply and exhaust of pressure fluid for said cylinder, valve throwing passages between opposed spaces in the valve chest and the cylinder bore for supplying pressure fluid for actuating said valve, and a. hole blowing device including means for venting the space at one end of the valve to atmosphere, said means including through said valve and manually operable from the opposite end of the valvecand said element having an abutment portion for directly engaging the Valve to hold the same immovable.

3. In a. fluid actuated rock drill of the hammer type, the combination of a cylinder and a piston reciprocable therein, a valve chest and a fluid distributing valve therein controlling both the supply and exhaust of pressure fluid for said cylinder, valve throwing passages between opposed spaces in the valve chest and the cylinder bore for supplying pressure fluid tor actuating said valve, and means including an auxiliary valve for venting the space ll one end of said distributing valve to atmosphere and including means for directly engaging said distribution valve to shift it into said space and hold the same immovable whereby said piston is held atthe rearward end of its stroke to eliect a hole blowing operation.

i. In a fluid actuated rock drill of the hammer type, the combination of a cylinder and a piston reciprocable therein, a valve he t and a nuid distributing valve therein controlling both the supply and exhaust of pressure fluid for said cylinder, valve throw ing passages between opposed spaces in the valve chest and the cylinder bore for supplying pressure fluid l'or controlling said valve, and means including a plurality of ports for one of said valve chest spaces, one of said ports leading directly to atmosphere, and an auxiliary valve for connectin said ports for venting the space at rear end or said valve an element extending to atmosphere, and means movable with said auxiliary valve for directly engaging the di: tributing valve to shift it toward the rear end and hold the same immovable whereby said piston is held at the rearward end of its stroke to effect a hole blowing operation.

5. In a fluid actuated roeh drill of the ham--- mer type, the combination of a. cylinder and a piston reciprocabletherein, a valve chest and a fluid distributing valve therein controlling both the supply and exhaust of pressure fluid for said cylinder, valve throwing passages between opposed spaces in the valve chest and the cylinder bore for supplying pressure fluid for actuating said valve, and

lie

a hole blowing device including means arit toward said end and hold the same immovable.

6. In a fluid actuated rock orillot the hammer type, the combination of a cylinder and valve chest I operation, and means a piston reciprocable therein, a valve chest and a fluid distributing valve therein controlling both the supply and exhaust of pressure fluid for said' cylinder, valve throwing passages between opposed spaces in the valve chest and the cylinder bore for supplying pressure liuid for actuating said valve, manually operable means for venting the valve chest space at one end of said valve to atmosphere and for directly engaging said valve to shift and hold the same immovable to cilifect a hole blowing operation, and means associated with said latter means for venting said valve chest spaces to atmosphere during normal operation of said valve.

Tin a fluid actuated rock drill of the hammer type, the combination of a cylinder and a piston rcciprocable therein, a valve chest and a lluid distributing valve therein controlling both the supply and exhaust of pressure liuid for said cylinder, valve throwing passages between opposed spaces in the valve chest and the cylinder bore for supplying pressure fluid for actuating said valve, means including an auxiliary valve for venting the valve chest space at one end of said valve to atmosphere and for directly engaging said di buting valve to shift and hold the same immovable to ei'ect a hole blowing associated with said auxilia valve for venting said valve chest spaces to atmosphere during normal operation of said fluid distributing valve.

8. In a tluid actuated r-oclc drill of the hammer type, the combination of a cylinder and a piston reciprocable therein, a valve chest and a fluid distributing valve therein controlling both the supply and exhaust of pressure fluid for said cylinder, valve throwing passages between opposed spaces in the valve chest and the cylinder bore for supplying pressure fluid tor actuating said valve, and

a hole blowing device including anauxiliary valve manually operable from the forward end of said distributing valve and'arranged coaxially therewith and extending theret-hro'ugh for venting the valvechest space at the rear end of said valve to atmosphere dur ing a hole blowing operation and for directly engaging said distributing valve to shift and hold the same immovable to effect a hole blowing operation. V

9. In a fluid actuated rock drill 01" the hammer type, the combination of a cylinder and a piston reciprocable therein, fluid distribution means for effecting reciprocation of said piston including a fluid distribution valve, and a hole blowing device comprising means including an element directly engaging said valve for mechanically shitting and holding the same in one position and. means controlled by a movement of said mechanical means for relieving the pressure tending to oppose shifting of the valve to the hole blowing position.

10. In a fluid actuated rock drill of the hammer type, the combination of a cylinder and a piston reciprocable therein, fluid dis tribution means including a fluid actuatedv reciprocable valve, valve throwing passages ietween opposed spaces in the valve chest and the cylinder bore for supplying pressure fluid M for actuating said valve, and a hole blowing device comprising manually operated means for engaging and mechanically moving and holding said valve in position to effect a hole blowing operation and valve means automatically operative on movement of said manual means prior to shifting of the valve to 'vent the pressure fluid in said space tending to oppose shifting of saidvalve toatmosphere.

In testimony whereof I afiix my signature.

CHARLES F. OSGOOD- 'III 

